org.apache.drill.exec.store.mongo.config.MongoPersistentStore.java Source code

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Here is the source code for org.apache.drill.exec.store.mongo.config.MongoPersistentStore.java

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/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.drill.exec.store.mongo.config;

import java.io.IOException;
import java.util.Iterator;
import java.util.Map.Entry;
import java.util.NoSuchElementException;

import com.google.common.base.Preconditions;
import org.apache.drill.common.exceptions.DrillRuntimeException;
import org.apache.drill.exec.store.mongo.DrillMongoConstants;
import org.apache.drill.exec.store.sys.BasePersistentStore;
import org.apache.drill.exec.store.sys.PersistentStoreConfig;
import org.apache.drill.exec.store.sys.PersistentStoreMode;
import org.bson.Document;
import org.bson.conversions.Bson;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.mongodb.client.MongoCollection;
import com.mongodb.client.MongoCursor;
import com.mongodb.client.model.Filters;
import com.mongodb.client.model.UpdateOptions;
import com.mongodb.client.model.Updates;
import com.mongodb.client.result.UpdateResult;

import static org.apache.drill.exec.store.mongo.config.MongoPersistentStoreProvider.pKey;

public class MongoPersistentStore<V> extends BasePersistentStore<V> {

    private static final Logger logger = LoggerFactory.getLogger(MongoPersistentStore.class);

    private final PersistentStoreConfig<V> config;
    private final MongoCollection<Document> collection;

    public MongoPersistentStore(PersistentStoreConfig<V> config, MongoCollection<Document> collection) {
        //    this.config = config;
        //    this.collection = collection;
        throw new UnsupportedOperationException("Mongo DB PStore not currently supported");
    }

    @Override
    public PersistentStoreMode getMode() {
        return PersistentStoreMode.PERSISTENT;
    }

    @Override
    public V get(String key) {
        try {
            Bson query = Filters.eq(DrillMongoConstants.ID, key);
            Document document = collection.find(query).first();
            if (document != null) {
                return value((byte[]) document.get(pKey));
            } else {
                return null;
            }
        } catch (Exception e) {
            logger.error(e.getMessage(), e);
            throw new DrillRuntimeException(e.getMessage(), e);
        }
    }

    @Override
    public void put(String key, V value) {
        try {
            Document putObj = new Document(DrillMongoConstants.ID, key).append(pKey, bytes(value));
            collection.insertOne(putObj);
        } catch (Exception e) {
            logger.error(e.getMessage(), e);
            throw new DrillRuntimeException(e.getMessage(), e);
        }
    }

    @Override
    public boolean putIfAbsent(String key, V value) {
        try {
            Bson query = Filters.eq(DrillMongoConstants.ID, key);
            Bson update = Updates.set(pKey, bytes(value));
            UpdateResult updateResult = collection.updateOne(query, update, new UpdateOptions().upsert(true));
            return updateResult.getModifiedCount() == 1;
        } catch (Exception e) {
            logger.error(e.getMessage(), e);
            throw new DrillRuntimeException(e.getMessage(), e);
        }
    }

    @Override
    public void delete(String key) {
        try {
            Bson query = Filters.eq(DrillMongoConstants.ID, key);
            collection.deleteOne(query);
        } catch (Exception e) {
            logger.error(e.getMessage(), e);
            throw new DrillRuntimeException(e.getMessage(), e);
        }
    }

    private byte[] bytes(V value) {
        try {
            return config.getSerializer().serialize(value);
        } catch (IOException e) {
            throw new DrillRuntimeException(e.getMessage(), e);
        }
    }

    private V value(byte[] serialize) {
        try {
            return config.getSerializer().deserialize(serialize);
        } catch (IOException e) {
            throw new DrillRuntimeException(e.getMessage(), e);
        }
    }

    @Override
    public Iterator<Entry<String, V>> getRange(int skip, int take) {
        final MongoCursor<Document> cursor = collection.find().skip(skip).limit(take).iterator();
        return new MongoIterator(cursor);
    }

    private class MongoIterator implements Iterator<Entry<String, V>> {

        private MongoCursor<Document> cursor;

        public MongoIterator(final MongoCursor<Document> cursor) {
            this.cursor = Preconditions.checkNotNull(cursor);
        }

        @Override
        public boolean hasNext() {
            return cursor.hasNext();
        }

        @Override
        public Entry<String, V> next() {
            if (!hasNext()) {
                throw new NoSuchElementException();
            }
            return new DeferredEntry(cursor.next());
        }

        @Override
        public void remove() {
            cursor.remove();
        }
    }

    private class DeferredEntry implements Entry<String, V> {

        private Document result;

        public DeferredEntry(Document result) {
            this.result = result;
        }

        @Override
        public String getKey() {
            return result.get(DrillMongoConstants.ID).toString();
        }

        @Override
        public V getValue() {
            return get(result.get(DrillMongoConstants.ID).toString());
        }

        @Override
        public V setValue(V value) {
            throw new UnsupportedOperationException();
        }
    }

    @Override
    public void close() {
    }
}